Recently, reduction in size and weight of a camera image-pickup device equipped in a camera or a cellular phone are advanced. In particular, a camera-mounted cellular phone is widespread among general users, and this makes it possible for users to casually pick up an image regardless of a location. However, fraudulent image-pickup, i.e., a secret-image-pickup action increases and becomes a problem in accordance with reduction in size and weight of a camera.
Because of the foregoing problem, a camera-mounted cellular phone has a function of emitting light when picking up an image, or of outputting sound (shutter sound) or the like for preventing secret image-pickup. This allows individuals around a user of the camera-mounted cellular phone to visibly recognize lighting-up of light, or to recognize sound, so that it is possible to notify an image-pickup action to the individuals therearound. As a result, it becomes possible to suppress any secret-image-pickup action in advance.
Moreover, various technologies have been developed as a technique of surely notifying an image-pickup action to people around a user of the camera-mounted cellular phone. For example, a technology disclosed in following patent literature 1 first measures a distance from an image-pickup device to an object based on the position of a lens focused by an auto-focus function of the image-pickup device. Next, an amount of light that is emitted to notify an image-pickup action (image-pickup notification light) is set based on the measured distance. More specifically, the farther the distance from the image-pickup device to the object is, the more the amount of light of the image-pickup notification light to be output is set. This enables notification of an image-pickup action more surely to an object located apart from the image-pickup device and individuals around the user of the image-pickup device.
Patent Literature 1: Unexamined Japanese Patent Application KOKAI Publication No. 2005-303719.